Finest crystals grow in solution
Minerals dissolve in water and form crystals. Halite (salt) melts easily while quartz takes much more time. Deep underground, increased pressure and temperature speed-up quartz crystal growth.
| With so many minerals dissolved in solution, why do some crystal species form instead of others? |
When examining ore veins, we often find a regular sequence of different crystals from top to bottom. Each crystal species forms under pressure-temperature conditions suitable for its growth. Thus crystals reflect the environment they grow in.
Rain, leaching, concentration A sulfide vein may evolve from a worthless deposit into valuable ore. This sketch shows how minerals change from top to bottom in a sulfide vein. Surface minerals weather; some minerals dissolve and leach through the soil before forming new or altered minerals. |
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Do metals form crystals?
Yes. We have difficulty seeing metal crystals after smoothing and polishing. Yet we can see large flat crystals of zinc in galvanized metal and smaller irregular crystals on freshly broken steel or cast iron.
| Exhibit inventory | |
| cast iron crystals | Use this magnifying glass to see the crystals. |
| zinc crystals | Zinc crystals formed on galvanized metal. |
* Visitors may touch these rocks or minerals.